Method of diagnosing alzheimers disease using saliva

Abstract

Provided is a method of diagnosing Alzheimer's disease. The method of diagnosing Alzheimer's disease includes preparing magnetic particles having primary capture antibodies specifically bonded with beta-amyloid adsorbed thereon, introducing saliva containing beta-amyloid into the magnetic particles to bond the beta-amyloid contained in the saliva with the primary capture antibodies, bonding secondary capture antibodies labeled with fluorescent substances to the magnetic particles bonded with the beta-amyloid to form a complex, disposing the complex in a channel region of an photoelectric conversion device in which photoelectric current is changed according to an amount of incident light, and measuring photoelectric current changed by light excited from the complex to quantify a concentration of the beta-amyloid contained in the saliva.

What is claimed is: 
     
         1 . A method of diagnosing Alzheimer's disease, the method comprising:
 preparing magnetic particles having primary capture antibodies specifically bonded with beta-amyloid adsorbed thereon;   introducing saliva containing beta-amyloid into the magnetic particles to bond the beta-amyloid contained in the saliva with the primary capture antibodies;   bonding secondary capture antibodies labeled with fluorescent substances to the magnetic particles bonded with the beta-amyloid to form a complex;   disposing the complex in a channel region of an photoelectric conversion device in which photoelectric current is changed according to an amount of incident light; and   measuring photoelectric current changed by light excited from the complex to quantify a concentration of the beta-amyloid contained in the saliva.   
     
     
         2 . The method of  claim 1 , wherein the photoelectric conversion device comprises an optical filter layer only transmitting a wavelength of excitation light excited from the fluorescent substances. 
     
     
         3 . The method of  claim 2 , wherein the optical filter layer is a Se (selenium) thin film. 
     
     
         4 . The method of  claim 2 , wherein the photoelectric conversion device comprises a semiconductor substrate, an insulation layer on the semiconductor substrate, a channel pattern on the insulation layer, and .interconnection electrodes disposed on the channel pattern by being spaced apart from each other. 
     
     
         5 . The method of  claim 4 , wherein the optical filter layer is disposed on the channel pattern. 
     
     
         6 . The method of  claim 1 , wherein the fluorescent substances are formed of a material emitting light having a wavelength band of 650 nm to 850 nm by excitation light having a wavelength ranging from 400 nm to 550 nm. 
     
     
         7 . The method of  claim 1 , wherein the magnetic particles comprise at least one selected from the group consisting of Fe (iron), Mn (manganese), Ni (nickel), and Co (cobalt). 
     
     
         8 . The method of  claim 1 , wherein a diameter of the magnetic particles is in a range of 100 nm to 5 μm. 
     
     
         9 . The method of  claim 1 , wherein the primary capture antibodies are bonded to the magnetic particles by a chemical reaction with EDC (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride) or CMC (1-cyclohexyl-3(2-morpholinoethyl)carbodiimide metho-p touluensulfonate). 
     
     
         10 . The method of  claim 1 , wherein the primary capture antibody is a monoclonal antibody and the secondary capture antibody is polyclonal antibody. 
     
     
         11 . The method of  claim 1 , further comprising bonding blocking molecules on surfaces of the magnetic particles not bonded with the primary capture antibodies. 
     
     
         12 . The method of  claim 1 , wherein the disposing of the complex in the channel region of the photoelectric conversion device is fixing the complex to the channel region by using an external magnetic field. 
     
     
         13 . The method of  claim 1 , wherein the primary capture antibody is adsorbed by a carboxyl group (—COOH), a thiol group (—SH), a hydroxyl group (—OH), a silane group, an amine group (—NH 2 ), or an epoxy group, derived on the surfaces of the magnetic particles. 
     
     
         14 . A method of diagnosing Alzheimer's disease, the method comprising:
 preparing comparison samples having different concentrations of beta-amyloid;   preparing magnetic particle samples having beta-amyloid contained in the each comparison sample combined with multiprotein;   measuring changes in photoelectric current from the magnetic particle samples by using an optical field effect transistor, in which photoelectric current is changed according to an amount of light, to generate reference data;   introducing saliva containing beta-amyloid to prepare magnetic particles having the beta-amyloid contained in the saliva bonded with the multiprotein;   measuring changes in photoelectric current from the magnetic particles by using the photoelectric conversion device to generate measurement data; and   comparing the reference data and the measurement data to diagnose the presence of Alzheimer's disease.   
     
     
         15 . The method of  claim 14 , wherein the concentration of beta-amyloid in the comparison samples is in a range of 1 pg/ml to 5,000 pg/ml.